Method and system for registering a medical situation associated with a first coordinate system, in a second coordinate system using an mps system

ABSTRACT

System for registering a first image with a second image, the system including a first medical positioning system for detecting a first position and orientation of the body of a patient, a second medical positioning system for detecting a second position and orientation of the body, and a registering module coupled with a second imager and with the second medical positioning system, the first medical positioning system being associated with and coupled with a first imager, the first imager acquiring the first image from the body, the first imager producing the first image by associating the first image with the first position and orientation, the second medical positioning system being associated with and coupled with the second imager, the second imager acquiring the second image and associating the second image with the second position and orientation, the registering module registering the first image with the second image, according to the first position and orientation and the second position and orientation.

FIELD OF THE DISCLOSED TECHNIQUE

The disclosed technique relates to medical devices in general, and tomethods and systems for acquiring images of the body of a patient, inparticular.

BACKGROUND OF THE DISCLOSED TECHNIQUE

A physician who performs an operation on the body of a patient,generally employs a real-time imaging system, in order to view thelocation and orientation of the medical intervention device (e.g.,catheter, needle), within the body of the patient during the operation.Such real-time imaging systems are known in the art. These systemsgenerally enable a display to display a representation of the medicalintervention device superimposed on an image of the body of the patient.

U.S. Pat. No. 6,351,513 issued to Bani-Hashemi et al., and entitled“Fluoroscopy Based 3-D Neural Navigation Based on Co-Registration ofOther Modalities with 3-D Angiography Reconstruction Data”, is directedto a method for displaying a real-time 3-D reconstruction of a catheterwithin a 3-D angiography reconstruction of a vessel. The method includesthe procedures of acquiring a 3-D angiography image of the arterial treeby a computed tomography device and registering the 3-D angiographyimage with a 2-D fluoroscopic image of a vessel, according to thestructural similarities (i.e., anatomical landmarks).

The method further includes the procedures of determining the projectinglines of the catheter by using an X-ray apparatus, determining thelocation of the catheter, by intersecting the 3-D angiography image withthe projecting lines and displaying a 3-D visualization of the 3-Dreconstruction of the catheter within the 3-D angiography reconstructionof the vessel. The 3-D visualization of the catheter is updated as thecatheter is moved.

U.S. Pat. No. 6,314,310 issued to Ben-Haim et al., and entitled “X-RayGuided Surgical Location System with Extended Mapping Volume”, isdirected to a system for inserting a needle into a selected location ofthe vertebrae of a patient. The system includes a reference element, aplurality of magnetic field generator coils, a driver circuitry, acomputer, a user interface control, a display, a fluoroscope and acomputer tomography (CT) device. The reference element is in form of aplastic disc transparent to visible light and X-rays, which includesthree equally spaced metal fiducial marks at the periphery thereof, afirst position and orientation sensing device at the center thereof andanother fiducial mark adjacent the first position and orientationsensing device. The needle includes a second position and orientationsensing device.

The magnetic field generator coils are placed on or adjacent to a bed onwhich the patient lies. The fluoroscope irradiates the patient from oneside of the body of the patient. The computer controls multiple aspectsof the system. The first position and orientation device and the secondposition and orientation device sends signals to the computer,respective of the time-varying magnetic fields generated by the magneticfield generator coils. The computer analyzes the signals to determinethe six-dimensional position and orientation coordinates of the firstposition and orientation device and the second position and orientationdevice, relative to a common frame of reference defined by the magneticfield generator coils. The computer enables the display to display animage of the vertebrae, a representation of the first position andorientation device and the second position and orientation device and arepresentation of the needle and the fiducial marks. The location andthe angular orientation of the reference element are determined bydetermining the two-dimensional coordinates of the representation of thefiducial marks. A scaling factor is determined for the images displayedon the display, by comparing the determined coordinates with the knownpositions of the fiducial marks.

While acquiring CT images of the body of the patient, the referenceelement is fixed to the body and remains fixed to the body in thisposition during the surgery. The CT images are registered with the X-rayimages, by comparing the image-derived coordinates of the fiducial marksof the reference element, which appear in the CT images, with theimage-derived coordinates of the fiducial marks in the X-ray images. Thefiducial marks of the reference element and the fiducial marks in theX-ray images are visible marks. The three-dimensional CT images arerotated or scaled, in order to align the CT images with the X-ray imagesand the CT images are projected onto the plane of the X-ray images andsuperimposed on the X-ray images or displayed alongside the X-rayimages.

U.S. Pat. No. 6,421,551 issued to Kuth et al., and entitled “Method forRegistering Images of a Subject with a Magnetic Resonance System andMagnetic Resonance System for the Implementation of the Method”, isdirected to a system for readjusting the tomogram plane of an image ofthe body of a patient. The system includes a control console, a magneticresonance system, a stereoscopic camera and a marking element. Thecontrol console includes a control unit, an image data generator andprocessor, a coordinate transformation unit, a readjustment unit and atomogram selecting unit. The magnetic resonance system includes two poleshoes which are located opposite one another.

The control console is connected to the magnetic resonance system and tothe stereoscopic camera. The marking element is composed of threereflective balls and is arranged at the patient in the region of theknee joint, in a first coordinate system. The stereoscopic cameraacquires an image of the reflective balls and sends the respectiveposition data to the control console. The coordinate transformation unittransforms the position data from the first coordinate system to asecond coordinate system of the magnetic resonance system. When therelative movement of the patient is known, the readjustment unitreadjusts the previously defined tomogram plane, such that it again liesrelative to the marking element with respect to the knee joint, as itdid in the preceding joint position.

One way to destroy tumors in a patient, and to prevent metastasis, is bysubjecting the target tissue to radiation therapy. One type of radiationtherapy is known as linear acceleration, whereby a beam of x-rays orelectrons is directed at the target tissue from different directions.Each time the linear accelerator directs a beam towards the targettissue it also irradiates healthy tissue which surrounds the targettissue, along the path of the irradiation beam. Accordingly, suchsurrounding tissue is irradiated significantly less than the targettissue.

The linear accelerator is programmed to irradiate a specific volumewhich is generally similar to the shape of the target tissue.Accordingly, the portion of the body including the target tissue, has tobe placed such that the target tissue is located within that specificvolume. A conventional linear acceleration treatment includes aplurality of recurring procedures, usually over a period of several daysor weeks. Each time, the portion of the body including the targettissue, has to be placed exactly as it was placed in the firsttreatment.

For this purpose, during the first radiation session, after locating theportion of the body which contains the target tissue at a locationappropriate for irradiation, a plurality of non-hazardous laser beams,for example four beams, are directed from fixed locations, toward thatportion of the body. These four points are marked by a permanent marker,such as a waterproof marker, on the skin of the patient. At everysubsequent session, that portion of the body is re-positioned to theposition and orientation determined at the first session, by directingthe same four laser beams toward the same portion of the body andrepositioning that portion, until the four permanent marks line up withthe four laser beams.

SUMMARY OF THE DISCLOSED TECHNIQUE

It is an object of the disclosed technique to provide a novel method andsystem for registering an image acquired in one coordinate system, withanother image acquired in another coordinate system.

In accordance with the disclosed technique, there is thus provided asystem for registering a first image with a second image. The systemincludes a first medical positioning system for detecting a firstposition and orientation of the body of a patient, a second medicalpositioning system for detecting a second position and orientation ofthe body, and a registering module. The registering module is coupledwith a second imager and with the second medical positioning system.

The first medical positioning system is associated with and coupled witha first imager. The first imager acquires the first image from the bodyand produces the first image by associating the first image with thefirst position and orientation. The second medical positioning system isassociated with and coupled with the second imager. The second imageracquires the second image and associates the second image with thesecond position and orientation. The registering module registers thefirst image with the second image, according to the first position andorientation and the second position and orientation.

Additionally, the system can include an image database coupled with thefirst imager and with the registering module. The first imager storesthe data respective of the first image acquired in the first coordinatesystem in the image database and the registering module retrieves thisdata from the image database, in order to register the first image withthe second image.

In accordance with another aspect of the disclosed technique, there isthus provided a method for registering a first image with a secondimage. The method includes the procedures of detecting a first positionand orientation of the body of a patient, in a first coordinate system,by a first medical positioning system and determining a first set ofcoordinates of the first image in the first coordinate system.

The method further includes the procedures of detecting a secondposition and orientation of the body, in a second coordinate system, bya second medical positioning system and determining a second set ofcoordinates of the second image in the second coordinate system. Themethod further includes the procedure of registering the first set ofcoordinates with the second set of coordinates.

In accordance with a further aspect of the disclosed technique, there isthus provided a system for re-positioning a portion of the body of apatient at the same therapeutic position and orientation suitable for atherapeutic device to medically treat a selected tissue of the bodyautomatically, during multiple therapeutic sessions. The system includesa positioning user interface, a position and orientation detector and amedical positioning system.

The position and orientation detector is located at a selected locationassociated with the selected tissue. The medical positioning system iscoupled with a storage unit, the positioning user interface and with theposition and orientation detector. The medical positioning systemdetects an initial position and orientation of the position andorientation detector, while the selected tissue is placed in thetherapeutic position and orientation. The medical positioning systemindicates via the positioning user interface when the position andorientation detector is placed again in the initial position andorientation, thereby establishing that the selected tissue is placedagain in the therapeutic position and orientation.

In accordance with another aspect of the disclosed technique, there isthus provided a method for re-positioning a portion of the body of apatient during a multi-session automatic therapeutic procedure. Themethod includes the procedures of detecting an initial position andorientation of a position and orientation detector, and recording theinitial position and orientation. The method further includes theprocedures of detecting the current position and orientation of theposition and orientation detector, at the beginning of each recurringmedical treatment and indicating whether the current position andorientation is substantially the same as the recorded position andorientation. The initial position and orientation is associated with atherapeutic position and orientation, suitable for automaticallytreating a selected tissue of the body.

In accordance with a further aspect of the disclosed technique, there isthus provided a system for medically treating a selected tissue withinthe body of a patient. The system includes a first medical positioningsystem, a second medical positioning system and a registering modulecoupled with the second medical positioning system and with atherapeutic device.

The first medical positioning system detects a first position andorientation of a position and orientation detector in a first coordinatesystem, when the position and orientation detector is coupled with thefirst medical positioning system. The position and orientation detectoris located at a selected location associated with the selected tissue.The second medical positioning system detects a second position andorientation of the position and orientation detector in a secondcoordinate system, when the position and orientation detector is coupledwith the second medical positioning system.

The registering module registers a set of coordinates of the selectedtissue in the first coordinate system, with the second coordinatesystem, wherein the set of coordinates is associated with the firstposition and orientation. The therapeutic device, then medically treatsthe selected tissue according to the registered set of coordinates.

In accordance with another aspect of the disclosed technique, there isthus provided a method for medically treating a selected tissue withinthe body of a patient. The method includes the procedures of detecting afirst position and orientation of a detector in a first coordinatesystem, by a first medical positioning system, and associating a set ofcoordinates of the selected tissue in the first coordinate system, withthe first position and orientation.

The method further includes the procedures of detecting a secondposition and orientation of the detector in a second coordinate system,by a second medical positioning system, and registering the associatedset of coordinates with the second coordinate system, according to thesecond position and orientation. The detector is located at a selectedlocation associated with the selected tissue.

In accordance with a further aspect of the disclosed technique, there isthus provided a system for adjusting an imager by means of a movingmechanism, to a desired orientation with respect to a section of thebody of a patient, to acquire a visual representation of the section ofthe body. The visual representation includes an optimal representationof a portion of interest of a medical intervention device. The medicalintervention device is inserted into the section of the body of thepatient.

The system includes a medical positioning system, a processor coupledwith the medical positioning system and with the moving mechanism, and adevice position and orientation detector coupled with the medicalintervention device at the portion of interest and with the medicalpositioning system. The medical positioning system detects a deviceposition and orientation of the device position and orientationdetector. The medical positioning system provides the device positionand orientation to the processor. The processor determines the desiredorientation, according to the detector position and orientation, and theprocessor directs the moving mechanism to move the imager to the desiredorientation.

Additionally, the system can include an imager position and orientationdetector coupled with the imager and with the medical positioningsystem. The medical positioning system detects an imager position andorientation of the imager and provides the imager position andorientation to the processor. The processor determines the desiredorientation, according to the device position and orientation and theimager position and orientation.

In accordance with another aspect of the disclosed technique, there isthus provided a method for adjusting an imager to a desired orientationto acquire a visual representation of a section of the body of apatient. The visual representation includes an optimal representation ofa portion of interest of a medical intervention device. The methodincludes the procedures of detecting a device position and orientationof a position and orientation detector coupled with the medicalintervention device, at the portion of interest, and determining thedesired orientation according to the device position and orientation,such that the imager can acquire the visual representation. The methodfurther includes the procedure of directing a moving mechanism to movethe imager to the desired orientation. The method can further includethe procedures of detecting an imager position and orientation of animager position and orientation detector coupled with the imager anddetermining the position and orientation of the imager from the imagerposition and orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed technique will be understood and appreciated more fullyfrom the following detailed description taken in conjunction with thedrawings in which:

FIG. 1A is a schematic illustration of a system for registering a firstimage acquired by a first imager, with a second image acquired by asecond imager, constructed and operative according to an embodiment ofthe disclosed technique;

FIG. 1B is a schematic illustration of a portion of the system of FIG.1A, which acquires the first image;

FIG. 1C is a schematic illustration of another portion of the system ofFIG. 1A, which acquires the second image and registers the first imagewith the second image;

FIG. 1D is a schematic illustration of each of the first medicalpositioning system (MPS) and the second MPS of the system of FIG. 1A;

FIG. 2A is a schematic illustration of a system for registering a firstreconstructed image with a second image acquired by a second imager,constructed and operative according to another embodiment of thedisclosed technique;

FIG. 2B is a schematic illustration of a portion of the system of FIG.2A, which reconstructs the first reconstructed image from a plurality oftwo-dimensional images;

FIG. 2C is a schematic illustration of another portion of the system ofFIG. 2A, which acquires the second image and registers the firstreconstructed image with the second image;

FIG. 2D is a schematic illustration of the portion of the system of FIG.2A, which acquires the second image by an image detector which isattached to a medical intervention device, and wherein this portion ofthe system registers the first reconstructed image with the secondimage;

FIG. 3A is a schematic illustration of two body position and orientationdetectors arranged on the body of a patient, to determine the scalefactor of an image, according to a further embodiment of the disclosedtechnique;

FIG. 3B is a schematic illustration of a first image of the body of thepatient, acquired by a first imager, similar to the first imager of FIG.1A;

FIG. 3C is a schematic illustration of a second image of the body of thepatient, acquired by a second imager similar to the second imager ofFIG. 1A, wherein the scale of the second image is different from thescale of the first image of FIG. 3B;

FIG. 3D is a schematic illustration of the first image of FIG. 3B,corrected according to the scale of the second image of FIG. 3C;

FIG. 4 is a schematic illustration of a portion of the system of FIG.1A, in which each of the first MPS and the second MPS is replaced by acoordinate determining unit, constructed and operative according toanother embodiment of the disclosed technique;

FIG. 5 is a schematic illustration of a portion of the system of FIG.1A, in which each of the first MPS and the second MPS is replaced by acoordinate determining unit, constructed and operative according to afurther embodiment of the disclosed technique;

FIG. 6 is a schematic illustration of a method for operating the systemof FIG. 1A, operative according to another embodiment of the disclosedtechnique;

FIG. 7 is a schematic illustration of a system for medically treating aselected tissue of a patient during a plurality of different treatmentsessions, constructed and operative according to a further embodiment ofthe disclosed technique;

FIG. 8 is a schematic illustration of a method for operating the systemof FIG. 7, operative according to another embodiment of the disclosedtechnique;

FIG. 9A is a schematic illustration of a system for registering theboundary of a selected tissue defined in the coordinate system of animager, with the coordinate system of a therapeutic device, constructedand operative according to a further embodiment of the disclosedtechnique;

FIG. 9B is a schematic illustration of an irradiation planning portionof the system of FIG. 9A;

FIG. 9C is a schematic illustration of a radiation treatment portion ofthe system of FIG. 9A;

FIG. 10 is a schematic illustration of a method for operating the systemof FIG. 9A, operative according to another embodiment of the disclosedtechnique;

FIG. 11 is a schematic illustration of a system for acquiring an imageof a medical intervention device, constructed and operative according toa further embodiment of the disclosed technique; and

FIG. 12 is a schematic illustration of a method for operating the systemof FIG. 11, operative according to another embodiment of the disclosedtechnique.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The disclosed technique overcomes the disadvantages of the prior art byproviding a non-visual registering system and method. The method ofdisclosed technique basically includes non-visually determining thecoordinates of a first image in a first coordinate system, non-visuallydetermining the coordinates of a second image in a second coordinatesystem and registering the first image with the second coordinatesystem, according to the determined coordinates. When the scaling of thefirst coordinate system and the scaling of the second coordinate systemare not the same, the scale of the first image is modified to match thatof the second coordinate system, such that when the first image and thesecond image are presented together, they are on the same scale.Furthermore, a representation of a medical intervention device, such ascatheter, needle, forceps, and the like, can be superimposed on thefirst image, by detecting the position and orientation of the medicalintervention device, via a detector attached to the medical interventiondevice.

In the following description, a coordinate system can be orthogonal,polar, cylindrical, and the like. It is noted that the term “image”herein below, refers to any type of visual representation of a selectedportion of the body of the patient, either acquired directly orreconstructed from raw measurements. Such an image can be provided inone, two or three spatial dimensions, still image or developing in time.It is noted that any of the MPS systems mentioned herein below may becoupled with the device or system associated therewith, eitherphysically (i.e., in a fixed location with respect thereto) or logically(i.e., where both collaborate within the same coordinate system). In thefollowing description, a medical intervention device can be a catheter(e.g., balloon catheter, stent catheter, surgical catheter, dilutioncatheter), drug delivery unit (e.g., needle, catheter having a coatedstent or a balloon, brachytherapy unit), tissue severing unit (e.g.,forceps, ablation catheter), and the like.

Reference is now made to FIGS. 1A, 1B, 1C and 1D. FIG. 1A, is aschematic illustration of a system for registering a first imageacquired by a first imager, with a second image acquired by a secondimager, generally referenced 100, constructed and operative according toan embodiment of the disclosed technique. FIG. 1B, is a schematicillustration of a portion of the system of FIG. 1A, which acquires thefirst image. FIG. 1C, is a schematic illustration of another portion ofthe system of FIG. 1A, which acquires the second image and registers thefirst image with the second image. FIG. 1D, is a schematic illustrationof each of the first medical positioning system (MPS) and the second MPSof the system of FIG. 1A, generally referenced 180.

With reference to FIG. 1A, system 100 includes a first MPS 102, a firstimager 104, an image database 106, a second imager 108, a second MPS 110and a registering module 112. Each of first MPS 102 and second MPS 110is a device which determines the position and orientation of athree-dimensional body (not shown), according to a signal received froma position and orientation detector (not shown), which is attached tothe three-dimensional body. Each of first MPS 102 and second MPS 110 issimilar to the MPS of U.S. Pat. No. 6,233,476, which is hereinincorporated by reference. Each of first MPS 102 and second MPS 110 canbe replaced by a position and orientation determining device whichdetermines the position and orientation of the three-dimensional body byperforming a triangulation operation on signals received from aplurality of detectors. These alternative position and orientationdetermining devices are described herein below in connection with FIGS.4 and 5.

Image database 106 is a data storage unit, such as magnetic memory unit(e.g., floppy diskette, hard disk, magnetic tape), optical memory unit(e.g., compact disk), volatile electronic memory unit (e.g., randomaccess memory), non-volatile electronic memory unit (e.g., read onlymemory, flash memory), remote network storage unit, and the like. Eachof first imager 104 and second imager 108 is a device which acquires animage of the body of a patient (not shown), (e.g., fluoroscopy,ultrasound, nuclear magnetic resonance—NMR, optical imaging,thermography, nuclear imaging—PET). Registering module 112 is a modulewhich registers the first image with the second image.

First imager 104 is coupled with first MPS 102 and with image database106. Second imager 108 is coupled with second MPS 110. Registeringmodule 112 is coupled with image database 106, second imager 108 andwith second MPS 110.

Alternatively, the system includes a plurality of medical systems (e.g.,imager, automated therapeutic system), each associated with an MPSsystem and all coupled together via a network (e.g., LAN, WAN, wired orwireless). It is noted that each of these MPS systems is spatiallycalibrated with the respective medical system associate therewith, suchthat both either share the same coordinate system or are able totranslate between the medical system coordinate system and the MPSsystem coordinate system.

With reference to FIG. 1B, a body position and orientation detector 130is attached to the body of a patient 132. Body position and orientationdetector 130 is similar to the sensor of U.S. Pat. No. 6,233,476 whichis herein incorporated by reference. Body position and orientationdetector 130 is either attached to the skin (not shown) of patient 132,placed under the skin, or implanted within the body of patient 132.Thus, body position and orientation detector 130 is fixed to the body ofpatient 132. First MPS 102 is coupled with body position and orientationdetector 130 and with first imager 104. First imager 104 is coupled withimage database 106.

First MPS 102 is associated with an X₁, Y₁, Z₁ coordinate system (i.e.,coordinate system I). First imager 104 is calibrated with first MPS 102,such that the position and orientation of first imager 104 is definedrelative to coordinate system I. Body position and orientation detector130 provides a signal respective of the position and orientationthereof, to first MPS 102. First MPS 102 determines the position andorientation of body position and orientation detector 130 in coordinatesystem I, according to the signal received from body position andorientation detector 130. First MPS 102 provides a signal respective ofthe position and orientation of body position and orientation detector130, to first imager 104. First imager 104 acquires a first image 134 ofthe body of patient 132 and stores in image database 106, the set ofcoordinates of first image 134 in coordinate system I, together with thecoordinates of body position and orientation detector 130 in coordinatesystem I.

Generally, this portion of system 100 (i.e., the stage of acquisition offirst image 134 from the body of patient 132), is performed prior toperforming a medical operation on patient 132. Hence, the imageacquisition stage as illustrated in FIG. 1B can be performed at aphysical location different than that of the image acquisition andmedical operation stage, as illustrated in FIG. 1C.

With reference to FIG. 1C, second MPS 110 is coupled with body positionand orientation detector 130, device position and orientation detector154, second imager 108 and with registering module 112. Registeringmodule 112 is coupled with image database 106 and with second imager108.

Second imager 108 acquires a second image (e.g., a second image 150) ofthe body of patient 132, while a clinical staff performs the medicaloperation on patient 132. Second MPS 110 is associated with an X₂, Y₂,Z₂ coordinate system (i.e., coordinate system II). Second imager 108 iscalibrated with second MPS 110, such that the position and orientationof second imager 108 is defined relative to coordinate system II.

Body position and orientation detector 130 provides a signal respectiveof the position and orientation thereof, to second MPS 110. Second MPS110 determines the position and orientation of the body position andorientation detector 130 in coordinate system II, according to thesignal received from body position and orientation detector 130. SecondMPS 110 provides a signal respective of the position and orientation ofbody position and orientation detector 130, to second imager 108. Secondimager 108 associates the set of coordinates of second image 150 incoordinate system II, with the position and orientation of position andorientation detector 130 in coordinate system II and provides arespective signal to registering module 112.

Registering module 112 retrieves from image database 106, the datarespective of the set of coordinates of first image 134 in coordinatesystem I, and the coordinates of body position and orientation detector130 in coordinate system I. Registering module 112 registers theposition and orientation of body position and orientation detector 130in coordinate system I, with the position and orientation of bodyposition and orientation detector 130 in coordinate system II. In thismanner, registering module 112 registers first image 134, which wasoriginally acquired in coordinate system I, with coordinate system II,such that both first image 134 and second image 150 can be presentedtogether within the same coordinate system II. It is noted thatregistering module 112 registers first image 134 with second image 150,by employing a position and orientation detector and without any visiblemarks or visible markers.

In case the scale of coordinate system I is not exactly the same as thatof coordinate system II, registering module 112 can change the scale offirst image 134 according to the scale factor between coordinate systemI and coordinate system II. This scale factor is stored in registeringmodule 112. For this purpose, more than one position and orientationdetector similar to body position and orientation detector 130, can beemployed, as described herein below, in connection with FIG. 3A.

Body position and orientation detector 130 is secured to a selectedpoint on or within the body of patient 132 and maintains substantiallythe same position and orientation relative to body of patient 132. Bodyposition and orientation detector 130 can be wired and include aconnector (not shown), in order to disconnect body position andorientation detector 130 from first MPS 102 and connect body positionand orientation detector 130 to second MPS 110. Alternatively, the bodyposition and orientation detector can be wireless.

Prior to, or during image acquisition by second imager 108, a medicalintervention device 152 may be inserted into the body of patient 132. Adevice position and orientation detector 154 is coupled with medicalintervention device 152. In the example set forth in FIG. 1C, medicalintervention device 152 is a catheter, and device position andorientation detector 154 is located at a distal end of the catheter. Inthe example set forth in FIG. 1A, first imager 104 is a CT device andsecond imager 108 is an X-ray device.

Device position and orientation detector 154 provides a signalrespective of the position and orientation of the distal end of thecatheter, to second MPS 110. Second MPS 110 determines the position andorientation of the distal end of the catheter in coordinate system II,according to the signal received from device position and orientationdetector 154. Second MPS 110 provides a signal respective of theposition and orientation of the distal end of the catheter, toregistering module 112.

Since in the example of FIG. 1C, second imager 108 is an X-ray deviceand the catheter is made of a radiopaque material, second image 150includes a real time image 156 of the catheter as well as an image ofthe body of patient 132.

Registering module 112 can be adapted either to merely transform andscale coordinates from a coordinate system I to coordinate system II orto provide image processing (e.g., superimposing images, adding visualrepresentations of devices). For example, registering module 112 cansuperimpose a real time representation 158 of the distal end of medicalintervention device 152 on first image 134, according to the signalreceived from second MPS 110. Registering module 112 provides a videosignal respective of first image 134 and second image 150 to a display(not shown) and the display displays first image 134 alongside secondimage 150. Thus, the clinical staff can view real time image 156 ofmedical intervention device 152 in second image 150 alongside real timerepresentation 158 of medical intervention device 152 in first image134.

In another example, registering module 112 superimposes first image 134on second image 150, after registering first image 134 with withincoordinate system II. In this case, the superimposed image (not shown)includes the first image, the second image, and either the real timeimage of medical intervention device or the real time visualrepresentation of medical intervention device.

With reference to FIG. 1D MPS 180 includes a position and orientationprocessor 182, a transmitter interface 184, a plurality of look-up tableunits 186 ₁, 186 ₂ and 186 ₃, a plurality of digital to analogconverters (DAC) 188 ₁, 188 ₂ and 188 ₃, an amplifier 190, a transmitter192, a plurality of MPS sensors 194 ₁, 194 ₂, 194 ₃ and 194 _(N) (i.e.,position and orientation detectors), a plurality of analog to digitalconverters (ADC) 196 ₁, 196 ₂, 196 ₃ and 196 _(N) and a sensor interface198.

Transmitter interface 184 is coupled with position and orientationprocessor 182 and with look-up table units 186 ₁, 186 ₂ and 186 ₃. DACunits 188 ₁, 188 ₂ and 188 ₃ are coupled with a respective one oflook-up table units 186 ₁, 186 ₂ and 186 ₃ and with amplifier 190.Amplifier 190 is further coupled with transmitter 192. Transmitter 192is also marked TX. MPS sensors 194 ₁, 194 ₂, 194 ₃ and 194 _(N) arefurther marked RX₁, RX₂, RX₃ and RX_(N), respectively.

Analog to digital converters (ADC) 196 ₁, 196 ₂, 196 ₃ and 196 _(N) arerespectively coupled with sensors 194 ₁, 194 ₂, 194 ₃ and 194 _(N) andwith sensor interface 198. Sensor interface 198 is further coupled withposition and orientation processor 182.

Each of look-up table units 186 ₁, 186 ₂ and 186 ₃ produces a cyclicsequence of numbers and provides it to the respective DAC unit 188 ₁,188 ₂ and 188 ₃, which in turn translates it to a respective analogsignal. Each of the analog signals is respective of a different spatialaxis. In the present example, look-up table 186 ₁ and DAC unit 188 ₁produce a signal for the X axis, look-up table 186 ₂ and DAC unit 188 ₂produce a signal for the Y axis and look-up table 186 ₃ and DAC unit 188₃ produce a signal for the Z axis.

DAC units 188 ₁, 188 ₂ and 188 ₃ provide their respective analog signalsto amplifier 190, which amplifies and provides the amplified signals totransmitter 192. Transmitter 192 provides a multiple axiselectromagnetic field, which can be detected by MPS sensors 194 ₁, 194₂, 194 ₃ and 194 _(N). Each of MPS sensors 194 ₁, 194 ₂, 194 ₃ and 194_(N) detects an electromagnetic field, produces a respective electricalanalog signal and provides it to the respective ADC unit 196 ₁, 196 ₂,196 ₃ and 196 _(N) coupled therewith. Each of the ADC units 196 ₁, 196₂, 196 ₃ and 196 _(N) digitizes the analog signal fed thereto, convertsit to a sequence of numbers and provides it to sensor interface 198,which in turn provides it to position and orientation processor 182.

Position and orientation processor 182 analyzes the received sequencesof numbers, thereby determining the position and orientation of each ofthe MPS sensors 194 ₁, 194 ₂, 194 ₃ and 194 _(N). Position andorientation processor 182 further determines distortion events andupdates look-up tables 186 ₁, 186 ₂ and 186 ₃, accordingly.

According to another aspect of the disclosed technique, a processorassociates each of a plurality of two-dimensional images acquired by afirst imager, with the position and orientation of the body of thepatient and with the position of each two-dimensional image in an organtiming signal (e.g., ECG) acquired by a first organ timing monitor. Theprocessor reconstructs a plurality of three-dimensional images from thetwo-dimensional images, according to the respective position andorientation of each two-dimensional image and its position within theorgan timing signal and the processor stores the reconstructedthree-dimensional images in an image database. A registering moduleretrieves a three-dimensional image from the image database according tothe current time point detected by a second organ timing monitor and theregistering module registers the retrieved three-dimensional image withanother image acquired by a second imager.

Reference is now made to FIGS. 2A, 2B, 2C and 2D. FIG. 2A, is aschematic illustration of a system for registering a first reconstructedimage with a second image acquired by a second imager, generallyreferenced 220, constructed and operative according to anotherembodiment of the disclosed technique. FIG. 2B, is a schematicillustration of a portion of the system of FIG. 2A, which reconstructsthe first reconstructed image from a plurality of two-dimensionalimages. FIG. 2C, is a schematic illustration of another portion of thesystem of FIG. 2A, which acquires the second image and registers thefirst reconstructed image with the second image. FIG. 2D, is a schematicillustration of the portion of the system of FIG. 2A, which acquires thesecond image by an image detector which is attached to a medicalintervention device, and wherein this portion of the system registersthe first reconstructed image with the second image.

With reference to FIG. 2A, system 220 includes a processor 222, a firstimager 224, a first MPS 226, a first organ timing monitor 228, an imagedatabase 230, a registering module 232, a second imager 234, a secondMPS 236 and a second organ timing monitor 238. Processor 222 is similarto the main computer of U.S. patent application Ser. No. 09/782,528,which is herein incorporated by reference. First imager 224 and secondimager 234 are similar to first imager 104 and second imager 108, asdescribed herein above in connection with FIG. 1A. Each of first organtiming monitor 228 and second organ timing monitor 238 is a device formonitoring the pulse rate of an inspected organ, such as the heart, thelungs, the eyelids, and the like. Each of first MPS 226 and second MPS236 is similar to MPS 180, as described herein above in connection withFIG. 1D.

Processor 222 is coupled with first imager 224, first MPS 226 firstorgan timing monitor 228 and with image database 230. First imager 224is coupled with first MPS 226. Registering module 232 is coupled withsecond imager 234, second MPS 236, second organ timing monitor 238 andwith image database 230. Second imager 234 is coupled with second MPS236.

With reference to FIG. 2B, an organ timing sensor 260 is attached to thebody of a patient 262, similar in the way that body position andorientation detector 130 (FIG. 1B) is attached to the body of patient132. A first pulse sensor 264 is attached to an organ (not shown) ofpatient 262, such as the heart, lungs, eyelids and the like. Organtiming sensor 260 is coupled with first MPS 226. First pulse sensor 264is coupled with first organ timing monitor 228. Processor 222 is coupledwith first imager 224, first MPS 226, first organ timing monitor 228 andwith image database 230. First imager 224 is coupled with first MPS 226.

First MPS 226 determines the position and orientation of organ timingsensor 260 in an X₁, Y₁, Z₁ coordinate system (i.e., coordinate systemI), according to a signal received from organ timing sensor 260. FirstMPS 226 provides a signal respective of the determined position andorientation of organ timing sensor 260, to processor 222 and to firstimager 224. First imager 224 acquires a plurality of two-dimensionalimages from the body of patient 262 and associates each of the acquiredtwo-dimensional images with the determined position and orientation oforgan timing sensor 260. First imager 224 provides a signal respectiveof the associated two-dimensional images to processor 222. First organtiming monitor 228 determines the timing signal of the organ of patient262, according to a signal received from first pulse sensor 264 andfirst organ timing monitor 228 provides a signal respective of thetiming signal to processor 222. The timing signal can be for example,the QRS wave of the heart (not shown).

Processor 222 associates each of the two-dimensional images with thecurrent time point of the timing signal. Processor 222 reconstructs aplurality of three-dimensional images from the two-dimensional images,according to the position and orientation of organ timing sensor 260 andaccording to the time points of the timing signal. Processor 222 storesthe reconstructed three-dimensional images in image database 230.

With reference to FIG. 2C, registering module 232 is coupled with secondimager 234, second MPS 236, second organ timing monitor 238 and withimage database 230. Second imager 234 is coupled with second MPS 236.Organ timing sensor 260 and device position and orientation detector 282are coupled with second MPS 236. Second pulse sensor 284 is coupled withsecond organ timing monitor 238.

A medical intervention device 280 is inserted into the body of patient262. In the example set forth in FIG. 2C, medical intervention device280 is a catheter. A device position and orientation detector 282 islocated at a distal end of medical intervention device 280. Deviceposition and orientation detector 282 detects the position andorientation of the distal end of medical intervention device 280. Asecond pulse sensor 284 is attached to the same organ of patient 262, towhich first pulse sensor 264 was attached. It is noted that first pulsesensor 264 and first organ timing monitor 228 can be employed in theembodiment of FIG. 2C, instead of second pulse sensor 284 and secondorgan timing monitor 238, respectively.

Second MPS 236 determines the position and orientation of organ timingsensor 260 in an X₂, Y₂, Z₂ coordinate system (i.e., coordinate systemII), according to a signal received from organ timing sensor 260. SecondMPS 236 further determines the position and orientation of the distalend of medical intervention device 280, according to a signal receivedfrom device position and orientation detector 282. Second MPS 236provides a signal respective of the determined position and orientationof organ timing sensor 260, to registering module 232 and to secondimager 234. Second MPS 236 provides a signal respective of thedetermined position and orientation of the distal end of medicalintervention device 280, to registering module 232.

Second imager 234 acquires a second image (e.g., a second image 286 asillustrated in FIG. 2C), from the body of patient 262 and associates thesecond image with the determined position and orientation of the body ofpatient 262. Second imager 234 provides a signal respective of theassociated second image to registering module 232. Second organ timingmonitor 238 determines the timing signal of the organ of patient 262,according to a signal received from second pulse sensor 284 and secondorgan timing monitor 238 provides a signal respective of the timingsignal to registering module 232.

Registering module 232 retrieves a three-dimensional image (e.g., athree-dimensional image 288 as illustrated in FIG. 2C) from imagedatabase 230, according to the determined position and orientation ofthe body of patient 262 and according to the current time point of thedetermined timing signal. Registering module 232 registersthree-dimensional image 288, which was acquired in coordinate system I,with coordinate system II which already includes second image 286, whichwas acquired in coordinate system II, in a similar manner as describedherein above in connection with first image 134 (FIG. 1C) and secondimage 150.

Registering module 232 produces different combinations ofthree-dimensional image 288, second image 286, a visual representationof the distal end of medical intervention device 280 and a real timeimage of medical intervention device 280. For example, registeringmodule 232 superimposes a real time visual representation 290 of thedistal end of medical intervention device 280 (in this case a catheter)on the retrieved three-dimensional image, thereby producingthree-dimensional image 288. Registering module 232 provides arespective video signal to a display (not shown). The display displaysthree-dimensional image 288 alongside second image 286.

In another example, registering module 232 superimposesthree-dimensional image 288 on second image 286. Second image 286 caninclude a real time image 292 of medical intervention device 280. Inthis case, the clinical staff can view a real time visual representation290 of medical intervention device 280, on a pseudo-real-timethree-dimensional image of the organ of the patient 262 (i.e.,three-dimensional image 288), wherein three-dimensional image 288 isconstantly updated according to the timing signal of the organ.Moreover, the clinical staff can view real time image 292 of medicalintervention device 280 on a real time image of the organ (i.e., secondimage 286) which generally includes less information than thepseudo-real-time three-dimensional image (i.e., three-dimensional image288).

With reference to FIG. 2D, registering module 232 is coupled with secondimager 316, second MPS 236, second organ timing monitor 238 and withimage database 230. Second imager 316 is coupled with second MPS 236 andwith image detector 314. Device position and orientation detector 312and organ timing sensor 260 are coupled with second MPS 236. Secondpulse sensor 284 is coupled with second organ timing monitor 238.

A medical intervention device 310, such as a catheter, is inserted intothe body of patient 262. A body position and orientation detector 312and an image detector 314 are located at a distal end of medicalintervention device 310. Image detector 314 is similar to the imagedetector of U.S. patent application Ser. No. 09/949,160, which is hereinincorporated by reference. Hence, image detector 314 can be an opticalcoherence tomography (OCT) imaging element, intravascular ultrasound(IVUS) transducer, magnetic resonance imaging (MRI) element,thermography imaging element, angiography imaging element, and the like.A second imager 316 produces a second image (e.g., a second image 318 asillustrated in FIG. 2D), according to a signal received from imagedetector 314.

Second MPS 236 determines the position and orientation of organ timingsensor 260 in coordinate system II, according to a signal received fromorgan timing sensor 260. Second MPS 236 determines the position andorientation of the distal end of medical intervention device 310,according to a signal received from device position and orientationdetector 312. Second MPS 236 provides a signal respective of thedetermined position and orientation of organ timing sensor 260, toregistering module 232 and to second imager 316. Second MPS 236 providesa signal respective of the determined position and orientation of thedistal end of medical intervention device 310, to registering module232.

Image detector 314 provides a signal to second imager 316, respective ofsurrounding objects (e.g., the intima of a blood vessel) and secondimager 316 produces a second image, such as second image 318, accordingto the received signal. Second imager 316 associates the second imagewith the determined position and orientation of organ timing sensor 260.Second imager 316 provides a signal respective of the associated secondimage to registering module 232. Second organ timing monitor 238determines the timing signal of the organ of patient 262, according to asignal received from second pulse sensor 284 and second organ timingmonitor 238 provides a signal respective of the timing signal toregistering module 232.

Registering module 232 retrieves a three-dimensional image (e.g., athree-dimensional image 320 as illustrated in FIG. 2D) from imagedatabase 230, according to the determined position and orientation oforgan timing sensor 260 and according to the current time point of thedetermined timing signal. Registering module 232 registersthree-dimensional image 320, which was acquired in coordinate system I,with second image 318, which was acquired in coordinate system II, in asimilar manner as described herein above in connection with first image134 (FIG. 1C) and second image 150.

Registering module 232 produces different combinations ofthree-dimensional image 320, second image 318, a visual representationof the distal end of medical intervention device 310 and a real timeimage of medical intervention device 310. For example, registeringmodule 232 superimposes a real time visual representation 322 of thedistal end of medical intervention device 310 (in this case a catheter)on the retrieved three-dimensional image, thereby producingthree-dimensional image 320. Registering module 232 provides arespective video signal to a display (not shown). This display displaysthree-dimensional image 320 alongside second image 318.

In another example, registering module 232 superimposesthree-dimensional image 320 on second image 318. Second image 318 caninclude a real time visual representation 324 of medical interventiondevice 310.

Reference is now made to FIGS. 3A, 3B, 3C and 3D. FIG. 3A, is aschematic illustration of two body position and orientation detectorsarranged on the body of a patient, to determine the scale factor of animage, according to a further embodiment of the disclosed technique.FIG. 3B is a schematic illustration of a first image of the body of thepatient, acquired by a first imager, similar to the first imager of FIG.1A. FIG. 3C is a schematic illustration of a second image of the body ofthe patient, acquired by a second imager similar to the second imager ofFIG. 1A, wherein the scale of the second image is different from thescale of the first image of FIG. 3B. FIG. 3D is a schematic illustrationof the first image of FIG. 3B, corrected according to the scale of thesecond image of FIG. 3C.

Body position and orientation detectors 350 and 352 are attached to abody 354 of a patient (not shown). Each of body position and orientationdetectors 350 and 352 is attached to body 354, in a way similar to theway body position and orientation detector 130 (FIG. 1A) is attached tothe body of patient 132. Body position and orientation detectors 350 and352 are incorporated with a system, such as system 100 (FIG. 1A). Hence,body position and orientation detectors 350 and 352 can be coupled witha first MPS similar to first MPS 102 (FIG. 1B), during image acquisitionand with a second MPS similar to second MPS 110 (FIG. 1C), while amedical operation is performed on the patient.

A registering module similar to registering module 112 (FIG. 1C) withwhich a second imager similar to second imager 108 is coupled, is notaware of the scale factor of the first image and of the second image,produced by the first imager and the second imager, respectively. Thedistance between body position and orientation detectors 350 and 352 isdesignated by the letter L.

With reference to FIG. 3B, a first imager similar to first imager 104(FIG. 1B), produces a first image 356 of an organ (not shown) of body354, in a display (not shown). Body position and orientation detectors350 and 352 are represented by two marks 358 and 360, respectively inthe display and the distance between marks 358 and 360 is designated byL₁.

With reference to FIG. 3C, a second imager similar to second imager 108(FIG. 1C), produces a second image 362 of the organ in the display. Bodyposition and orientation detectors 350 and 352 are represented by twomarks 364 and 366, respectively in the display and the distance betweenmarks 364 and 366 is designated by L₂.

In the example set forth in FIGS. 3B and 3C, the scale of first image356 is twice that of second image 362 (i.e., L₁=2 L₂). In order toprovide the correct impression of the first image and the second imageto a viewer (not shown), the first image and the second image have to bedisplayed at substantially the same scale.

With reference to FIG. 3D, the registering module scales down firstimage 356 by 200%, thereby producing another first image 368. Bodyposition and orientation detectors 350 and 352 are represented by twomarks 370 and 372, respectively in the display and the distance betweenmarks 370 and 372 is L₁ (i.e., the same as that of marks 364 and 366).Thus, first image 368 and second image 362 are displayed side by side,at substantially the same scale.

Reference is now made to FIG. 4, which is a schematic illustration of aportion of the system of FIG. 1A, in which each of the first MPS and thesecond MPS is replaced by a coordinate determining unit, generallyreferenced 390, constructed and operative according to anotherembodiment of the disclosed technique. Coordinate determining unit (CDU)390 includes a transceiver 392, a processor 394 and a plurality ofsensing units 396 ₁, 396 ₂ and 396 _(N).

In a system similar to system 100 (FIG. 1A), first MPS 102 can bereplaced with a first CDU and second MPS 110 can be replaced by a secondCDU. The first CDU includes a first transceiver and a first processor,and the second CDU includes a second transceiver and a second processor.The first CDU is associated with a first coordinate system similar tocoordinate system I (FIG. 1B) and the second CDU is associated with asecond coordinate system similar to coordinate system I (FIG. 1C).

The first processor is coupled with the first transceiver and with afirst imager similar to first imager 104 (FIG. 1A), and the secondprocessor is coupled with a second imager similar to second imager 108and with a registering module similar to registering module 112. In animage acquisition stage similar to the one illustrated herein above inFIG. 1B, sensing units 396 ₁, 396 ₂ and 396 _(N) are coupled with thefirst transceiver. In an image registration stage similar to the oneillustrated herein above in FIG. 1C, sensing units 396 ₁, 396 ₂ and 396_(N) are coupled with the second transceiver.

Each of sensing units 396 ₁, 396 ₂ and 396 _(N) is attached to the body398 of a patient (not shown), similar to the way body position andorientation detector 130 (FIG. 1B), is attached to the body of patient132. Each of sensing units 396 ₁, 396 ₂ and 396 _(N) includes a locationdetector and an orientation detector. The location detector can be anelectromagnetic coil, sonar sensor (e.g., ultrasound), and the like.

The orientation detector can be a miniature gyroscope, and the like.This type of gyroscope includes an oscillating chip mounted element anda plurality of sensors and it is sold under the trademark GyroChip™, byBEI Systron Donner Inertial Division, Germany. The oscillating elementoscillates by a quartz element and the sensors produce a currentproportional to rotation of the oscillating element about an axis of thesensors. Transceiver 392 is coupled with processor 394 and with sensingunits 396 ₁, 396 ₂ and 396 _(N).

Transceiver 392 transmits a signal (e.g., electromagnetic or acoustic),toward the location detector of each of sensing units 396 ₁, 396 ₂ and396 _(N). The location detector of each of sensing units 396 ₁, 396 ₂and 396 _(N) transmits a signal respective of the location thereof, totransceiver 392, via a respective wiring. The orientation detector ofeach of sensing units 396 ₁, 396 ₂ and 396 _(N) transmits a signalrespective of the orientation thereof, to transceiver 392, via anotherrespective wiring. Processor 394 determines the position and orientationof body 398 according to the signals received by transceiver 392.

Additionally, a medical intervention device 400 can be inserted intobody 398 and a sensing unit 402 can be attached to a distal end ofmedical intervention device 400 and sensing unit 402 can be coupled withtransceiver 392. Sensing unit 402 is similar to each of sensing units396 ₁, 396 ₂ and 396 _(N). In this case, processor 394 can determine theposition and orientation of the distal end of medical interventiondevice 400, according to signals received from sensing unit 402.

Further additionally, an imager 404, such as an ultrasound transducer,OCT element, MRI element, thermography element, angiography element, andthe like, can be employed to acquire an image of body 398. In this case,a sensing unit 406 is attached to imager 404 and sensing unit 406 iscoupled with transceiver 392. Sensing unit 406 is similar to each ofsensing units 396 ₁, 396 ₂ and 396 _(N). Processor 394 determines theposition and orientation of imager 404 according to signals receivedfrom sensing unit 406 and sensing units 396 ₁, 396 ₂ and 396 _(N), bytransceiver 392.

Reference is now made to FIG. 5, which is a schematic illustration of aportion of the system of FIG. 1A, in which each of the first MPS and thesecond MPS is replaced by a coordinate determining unit, generallyreferenced 430, constructed and operative according to a furtherembodiment of the disclosed technique. Coordinate determining unit 430includes a plurality of receivers 432 ₁, 432 ₂ and 432 _(N), a processor434 and a plurality of transmitters 436 ₁, 436 ₂ and 436 _(N).Transmitters 436 ₁, 436 ₂ and 436 _(N) are attached to a body 438 of apatient (not shown), similar to the way body position and orientationdetector 130 (FIG. 1B), is attached to the body of patient 132.Receivers 432 ₁, 432 ₂ and 432 _(N), are coupled with processor 434.

Each of transmitters 436 ₁, 436 ₂ and 436 _(N) transmits a signal toreceivers 432 ₁, 432 ₂ and 432 _(N). This signal can be electromagnetic(e.g., radio frequency or radio pulses), optic (e.g., infrared),acoustic (e.g., ultrasound), and the like. Processor 434 determines theposition and orientation of body 438 according to signals received fromreceivers 432 ₁, 432 ₂ and 432 _(N) and by employing a triangulationmethod.

Reference is now made to FIG. 6, which is a schematic illustration of amethod for operating the system of FIG. 1A, operative according toanother embodiment of the disclosed technique. In procedure 460, a firstposition and orientation of the body of a patient is detected in a firstcoordinate system, by a first medical positioning system. With referenceto FIG. 1B, first MPS 102 determines the position and orientation of thebody of patient 132 in coordinate system I, according to a signalreceived from body position and orientation detector 130. It is notedthat first MPS 102 and body position and orientation detector 130, canbe replaced by either coordinate determining unit 390 (FIG. 4) orcoordinate determining unit 430 (FIG. 5).

In procedure 462, a first image of the body of the patient is acquiredby a first imager. With reference to FIG. 1B, first imager 104 acquiresfirst image 134 of the body of patient 132.

In procedure 464, a first set of coordinates of the first image isdetermined in the first coordinate system. With reference to FIG. 1B,first imager 104 determines the set of coordinates of first image 134 incoordinate system I, and stores in image database 106, this set ofcoordinates together with the coordinates of body position andorientation detector 130 which were detected in procedure 460.

In procedure 466, a second position and orientation of the body of thepatient is detected in a second coordinate system, by a second medicalpositioning system. With reference to FIG. 1C, second MPS 110 determinesthe position and orientation of body position and orientation detector130 in coordinate system II, according to a signal received from bodyposition and orientation detector 130. It is noted that second MPS 110and body position and orientation detector 130, can be replaced byeither coordinate determining unit 390 (FIG. 4) or coordinatedetermining unit 430 (FIG. 5).

In procedure 468, a second image of the body of the patient is acquiredby a second imager. With reference to FIG. 1C, second imager 108acquires second image 150 of the body of patient 132.

In procedure 470, a second set of coordinates of the second image isdetermined in a second coordinate system. With reference to FIG. 1C,second imager 108 determines the set of coordinates of second image 150in coordinate system II and associates this set of coordinates with thecoordinates of body position and orientation detector 130, which weredetected in procedure 466.

In procedure 472, the first set of coordinates is registered in thesecond coordinate system and as a result, with the second set ofcoordinates. With reference to FIG. 1C, registering module 112 retrievesthe data respective of the set of coordinates of first image 134 incoordinate system I and the coordinates of body position and orientationdetector 130 in coordinate system I, from image database 106.Registering module 112 receives a signal respective of the set ofcoordinates of second image 150 in coordinate system II and thecoordinates of body position and orientation detector 130 in coordinatesystem II, from second imager 108. Registering module 112 registersfirst image 134 in coordinate system II and as a result, with secondimage 150, by registering the coordinates of body position andorientation detector 130 in coordinate system I, with the coordinates ofbody position and orientation detector 130 in coordinate system II.

Registering module 112 also receives a signal from second MPS 110,respective of the position and orientation of the distal end of medicalintervention device 152. Registering module 112 superimposes real timevisual representation 158 of the distal end of medical interventiondevice 152 on first image 134. First image 134 and second image 150 canbe displayed side by side in a display, or superimposed on one another.

According to another aspect of the disclosed technique, a selectedposition and orientation of a selected tissue of the body of a patient,is recurrently obtained relative to a therapeutic device, by a medicalpositioning system. The selected position and orientation, which is theone which is suitable for the selected tissue to be effectivelymedically treated by the therapeutic device, is detected once during thefirst treatment, and stored in a database. At the start of everysubsequent treatment, the portion of the body of the patient isre-positioned such that the currently detected position and orientationof the detector substantially matches the selected position andorientation.

The term “selected tissue” herein below, refers to a tissue of the bodyof a patient, either internal (i.e., internal organs of the body) orexternal (e.g., skin, nails, or cornea) which is to be operated on(e.g., by irradiation, or by surgery). The selected tissue can be atumoral part of an organ of the body, such as hyperplasia (i.e., atissue having an excessive number of cells), neoplasia (formation of newtissue), benign tumor, malignant tumor, carcinoma, and the like (in caseof irradiation), or a non-tumoral part of an organ of the body, such asbrain, liver, lungs, kidneys, and the like (in case of surgery).

Reference is now made to FIG. 7, which is a schematic illustration of asystem for medically treating a selected tissue of a patient during aplurality of different treatment sessions, generally referenced 500,constructed and operative according to a further embodiment of thedisclosed technique. System 540 includes an MPS 502, a positioning userinterface 504, a storage unit 506, a therapeutic device 508 and a movingmechanism 510.

MPS 502 is similar to first MPS 102 (FIG. 1A), as described hereinabove. Positioning user interface 504 is a tactile, audio, visual,kinesthetic user interface, and the like. Storage unit 506 is a magneticmemory unit, optical memory unit, integrated circuit, and the like, suchas hard disk, floppy diskette, compact disk, magnetic tape, flashmemory, random access memory, read only memory, and the like.

Therapeutic device 508 is a tissue treating device such as a linearaccelerator, local robotic surgical device, remote tele-surgical device,and the like. A linear accelerator is a device which produces highenergy X-rays and electron beams, and bombards the selected tissuelocated at a predetermined point or volume in space, from differentdirections. A local robotic surgical device is a device which isoperated by the clinical staff from a substantially close distance fromthe patient, such as from a control room in the same hospital. A remotetele-surgical device is a device which is operated by the clinical stafffrom a remote location, via a network, such as local area network (LAN),wide area network (WAN) (e.g., the Internet), metropolitan area network(MAN), and the like. Moving mechanism 510 is coupled with therapeuticdevice 508, in order to move therapeutic device 508 to differentorientations and enable therapeutic device 508 to bombard the selectedtissue from different directions. In general, a moving mechanism isadapted to move either the therapeutic device or the patient or both,relative to one another.

Therapeutic device 508 can for example, be in form of a C-arm which isfree to rotate about one axis, thus having one degree of freedom.Alternatively, therapeutic device 508 can have more than one degrees offreedom. In the example set forth in FIG. 7, therapeutic device 508 is alinear accelerator. Moving mechanism 510 is an electromechanical element(e.g., rotary or linear electric motor including power transmissionelements, such gears, pulleys and belts), electromagnetic element (e.g.,an electromagnetic coil and a moving core, and vice versa), hydraulicelement, pneumatic element, and the like.

A detector 512 is implanted in the body of a patient 514, at a selectedlocation associated with a selected tissue 516 located within the bodyand it is fixed at this location, during the period that patient 514 isunder medical treatment. Detector 512 is similar to body position andorientation detector 130 (FIG. 1B), as described herein above. Detector512 can be implanted in the body, either invasively (i.e., by performingan incision), or non-invasively (e.g., with the aid of a needle—notshown, or a catheter—not shown). In case a catheter is employed,detector 512 is coupled with a distal end of the catheter, and detector512 is inserted into the body with the aid of the catheter. Detector 512is left in the body for the entire treatment period. In the example setforth in FIG. 7, detector 512 is implanted within selected tissue 516.

Detector 512 is coupled with MPS 502 by a wiring 520 and a quickdisconnect plug (not shown). Detector 512 can be plugged into MPS 502prior to the start of every treatment session and disconnected after thesession. MPS 502 is coupled with positioning user interface 504.Alternatively, the detector is coupled with the MPS wirelessly.

During the first treatment session, the clinical staff (not shown)positions a portion of the body of patient 514 to a position andorientation (i.e., therapeutic position and orientation), such thatselected tissue 516 is located at a position and orientation suitablefor therapeutic device 508 to effectively treat selected tissue 516. Atthis point, MPS 502 detects the position and orientation of detector 512(i.e., an initial position and orientation) and the clinical staffstores this initial position and orientation in storage unit 506, viapositioning user interface 504.

Prior to the start of every subsequent treatment session, the clinicalstaff couples detector 512 with MPS 502. Patient 514 lies on anoperating table 518 and the clinical staff positions a portion of thebody of patient 514 at the therapeutic position and orientation, suchthat the position and orientation of detector 512 is substantiallyidentical with the stored position and orientation. At this time, thisportion of the body of patient 514 is in the same position andorientation as in the first treatment session.

It is noted that system 500 enables the clinical staff to repeatedlyreposition the body of patient 514 at each subsequent treatment session,at the same position and orientation as in the first treatment session.It is further noted that operating table 518 can be replaced by anotherconfinement device, adapted to secure selected tissues in place, duringa treatment session.

The clinical staff can determine the therapeutic position andorientation of the body, for example, by comparing the position andorientation of detector 512 detected in a subsequent treatment session(i.e., an intermediate position and orientation), with the one detectedduring the first treatment session (i.e., the initial position andorientation). For this purpose, positioning user interface 504 producesrepresentations of these two positions and orientations, for example,visually, acoustically, kinesthetically, and the like. After positioningthe portion of the body of patient 514 at the therapeutic position andorientation, and maintaining this therapeutic position and orientation,the clinical staff directs therapeutic device 508, to automaticallytreat selected tissue 516 (e.g., when using a linear accelerator, toirradiate the selected tissue from different directions).

A controller (not shown) can be coupled with therapeutic device 508 andwith moving mechanism 510. The system can further include another atherapeutic device user interface (not shown), coupled with thecontroller. The controller can be programmed to control moving mechanism510 to move therapeutic device 508, in order to medically treat selectedtissue 516 from these directions. This program is fixed and invariableand is permanently stored in the controller. Alternatively, the clinicalstaff can alter the program by entering the respective parameters to thecontroller, via the therapeutic device user interface.

The controller is further coupled with MPS 502. MPS 502 detects theposition and orientation of detector 512 and provides a respectivesignal to the controller. The controller directs moving mechanism 510 tomove therapeutic device 508 according to the signal received from MPS502, in a closed loop (i.e., according to feedback from MPS 502). Inthis manner, the controller directs moving mechanism 510 to change theposition and orientation of therapeutic device 508, according to changesin the position and orientation of selected tissue 516 (i.e., movementsof the body of patient 514).

Thus, system 500 enables the clinical staff to treat patient 514 whilepatient 514 is in an unrestrained position and free to move. The qualityof treatment in the unrestrained position is substantially the same thanin the case where the body of patient 514 is restrained and therapeuticdevice 508 does not follow the movements of patient 514 in a closedloop.

Further alternatively, the clinical staff enters a set of coordinatesrespective of the boundary of the selected tissue to the controller, viathe therapeutic device user interface. The controller controls themoving mechanism to move the therapeutic device according to the enteredset of coordinates, in order to automatically medically treat theselected tissue. The entered set of coordinates can be either discrete(i.e., numerical values), or volumetric (e.g., radius of a sphere from areference point, height, width and depth of a cube, or radius of thebase of a cylinder and the height thereof).

Further alternatively, the moving mechanism is coupled with theoperating table and the controller is coupled with the moving mechanismand with the therapeutic device user interface. The clinical staffenters a set of coordinates respective of the boundary of the selectedtissue to the controller, via the therapeutic device user interface. Thecontroller controls the moving mechanism to move the operating tableaccording to the entered set of coordinates, in order to allow thetherapeutic device to medically treat the selected tissue.

Further alternatively, the moving mechanism is coupled both with thetherapeutic device and the operating table. In any case, the movingmechanism provides movement of the selected tissue relative to thetherapeutic device, in order to allow the therapeutic device tomedically treat the selected tissue.

Alternatively, a comparator (not shown) is coupled with MPS 502, storageunit 506 and with positioning user interface 504, wherein the comparatorcompares the position and orientation of the detector at a subsequenttreatment session, with the one detected during the first treatmentsession. The comparator provides a signal to positioning user interface504, when the comparator determines that the stored position andorientation is substantially identical to the currently detectedposition and orientation.

Positioning user interface 504 produces an indication, such as anaudible sound, a visual cue, a tactile indication, and the like,according to the signal received from the comparator. The clinical staffdetermines according to this indication, that the portion of the body ofpatient 514 is located at a position and orientation, suitable forselected tissue 516 to be medically treated by the therapeutic device.Further alternatively, the detector can be implanted at a selectedlocation so close to the selected tissue, that the clinical staff canassure that when the detector is located at the selected position andorientation, the position and orientation of the selected tissue issuitable for medical treatment.

Reference is now made to FIGS. 8, which is a schematic illustration of amethod for operating the system of FIG. 7, operative according toanother embodiment of the disclosed technique. In procedure 522, aninitial position and orientation of a fixed detector is detected,wherein the initial position and orientation is associated with atherapeutic position and orientation, suitable for automaticallytreating a selected tissue of the body of a patient. With reference toFIG. 7, MPS 502 detects the position and orientation of detector 512,when detector 512 is at a position and orientation (i.e., a therapeuticposition and orientation), suitable for therapeutic device 508 toautomatically treat selected tissue 516.

Detector 512 is previously implanted by the clinical staff, withinselected tissue 516. Alternatively, the position and orientationdetector can be implanted at a location which is substantially close tothe selected tissue (i.e., the spatial relations between the positionand orientation detector and the selected tissue should remain unchangedat all times), so that the clinical staff can assure that this positionand orientation, determines a position and orientation for the selectedtissue to be effectively treated by the therapeutic device.

In procedure 524, the initial position and orientation is recorded. Withreference to FIG. 7, MPS 502 stores in storage unit 506, the positionand orientation of detector 512, as detected in procedure 522.Alternatively, the clinical staff stores a set of coordinates respectiveof the position and orientation of detector 512 corresponding with thetherapeutic position and orientation, via positioning user interface504. This set of coordinates can be determined at the treatment planningstage, for example according to an image of the selected tissue.

In procedure 526, the current position and orientation of the fixeddetector is detected, at the beginning of each recurring medicaltreatment. With reference to FIG. 7, during each subsequent treatmentsession and before the medical treatment, MPS 502 detects the positionand orientation of detector 512, while the clinical staff moves aportion of the body of patient 514 which includes selected tissue 516.Following procedure 526 the method can proceed either to procedure 528or to procedure 532.

In procedure 528, it is indicated whether the current position andorientation is substantially the same as the recorded initial positionand orientation. With reference to FIG. 7, as the clinical staff movesthe portion of the body of patient 514 which includes selected tissue516, positioning user interface 504 indicates whether the currentposition and orientation of detector 512 is substantially the same asthe one which was recorded in procedure 524. Positioning user interface504 produces indications respective of the current position andorientation of detector 512 and the recorded position and orientation(e.g., visually), and the clinical staff moves patient 514 accordingly.Alternatively, positioning user interface 504 notifies (e.g., audibly)the clinical staff that the current position and orientation of detector512 substantially matches the initial position and orientation asrecorded in procedure 524.

In procedure 530, the selected tissue is medically treated, whilemaintaining the detector at the recorded initial position andorientation. With reference to FIG. 7, therapeutic device 508 medicallytreats selected tissue 516 (e.g., irradiating selected tissue 516 fromdifferent directions), while the clinical staff maintains detector 512,and thus selected tissue 516, at the position and orientation which wasrecorded in procedure 524.

In procedure 532, a therapeutic device is directed to an orientationsuitable for automatically treating the selected tissue, when thecurrent position and orientation is substantially the same as therecorded initial position and orientation. In this case, in a systemsimilar to system 500 (FIG. 7), the MPS is coupled with the therapeuticdevice. Whenever the position and orientation of the detector and thusof the selected tissue is substantially the same as that of the recordedinitial position and orientation, the MPS directs the therapeutic deviceto automatically treat the selected tissue.

According to a further aspect of the disclosed technique, one of thecoordinate systems is that of an automated medical therapeutic device.In the following example, the automated medical therapeutic system is alinear accelerator, used for irradiating a selected point by irradiatinga plurality of axes which cross it. Here, a position and orientationdetector is placed within the body of the patient, at a selectedlocation associated with a selected tissue. The clinical staffdetermines the position and orientation of a portion of the body at theplanning stage and records the position and orientation of the detector.At the radiation treatment stage, a registering module registers theposition and orientation of the detector at the radiation treatmentstage with the one determined during the planning stage. The clinicalstaff, then repositions the portion of the body, such that the positionand orientation of the detector is substantially the same as the onedetermined at the planning stage and directs the therapeutic device toirradiate the selected tissue.

Reference is now made to FIGS. 9A, 9B and 9C. FIG. 9A is a schematicillustration of a system for registering the boundary of a selectedtissue defined in the coordinate system of an imager, with thecoordinate system of a therapeutic device, generally referenced 540,constructed and operative according to a further embodiment of thedisclosed technique. FIG. 9B is a schematic illustration of anirradiation planning portion of the system of FIG. 9A. FIG. 9C is aschematic illustration of a radiation treatment portion of the system ofFIG. 9A.

With reference to FIG. 9A, system 540 includes an imager MPS 542, a userinterface 544, an imager 546, a storage unit 548, an irradiator MPS 550,a registering module 552 and an irradiating unit 554. Irradiating unit554 includes a controller 556, an irradiator 558 and a moving mechanism560. Imager 546 is coupled with imager MPS 542, user interface 544 andwith storage unit 548. Storage unit 548 is coupled with imager MPS 542.Registering module 552 is coupled with storage unit 548, irradiator MPS550 and with irradiating unit 554. Controller 556 is coupled withirradiator 558 and with moving mechanism 560.

Imager MPS 542, imager 546, irradiator MPS 550 and registering module552 are similar to first MPS 102 (FIG. 1A), first imager 104, second MPS110 and registering module 112, respectively, as described herein above.Imager 546 can be a three-dimensional type imager, such as computertomography, ultrasound, and the like. Storage unit 548 and movingmechanism 560 are similar to storage unit 506 (FIG. 7) and movingmechanism 510, respectively, as described herein above. User interface544 is a tactile user interface, audio, visual, and the like, such as akeyboard, mouse, stylus, microphone, display (e.g., touch-screendisplay), and the like, or a combination thereof. Irradiator 558 issimilar to the linear accelerator, as described herein above inconnection with therapeutic device 508 (FIG. 7).

With reference to FIG. 9B, imager 546 is coupled with imager MPS 542 andwith storage unit 548. Imager MPS 542 is coupled with storage unit 548.A position and orientation detector 562 is placed at a selected locationassociated with a selected tissue 564 of a patient 566, similar to theway detector 512 (FIG. 7), is placed within the body of patient 514.Alternatively, position and orientation detector 562 can be insertedinto the body of patient 566, at the selected location, by employing abody intrusion device (not shown), such as a catheter, needle, and thelike. Position and orientation detector 562 is similar to body positionand orientation detector 130 (FIG. 1B), as described herein above.Patient 566 lies on an operating table 568.

Imager MPS 542 is associated with an X₁, Y₁, Z₁ coordinate system (i.e.,coordinate system I). Imager 546 is calibrated with imager MPS 542, suchthat the position and orientation of imager 546 is defined relative tocoordinate system I. Position and orientation detector 562 provides asignal respective of the position and orientation thereof, to imager MPS542 via wiring 570 (alternatively, wirelessly). Imager MPS 542determines the position and orientation of position and orientationdetector 562 in coordinate system I, according to the signal receivedfrom position and orientation detector 562.

Imager MPS 542 provides a signal respective of the position andorientation of position and orientation detector 562, to imager 546.Imager 546 produces a signal respective of a planning stage image 572 ofa tissue image 574 of selected tissue 564 and a detector image 576 ofposition and orientation detector 562. Planning stage image 572 can beeither two-dimensional or three-dimensional. Imager 546 provides thissignal to user interface 544 and user interface 544 displays planningstage image 572, according to the received signal. Detector image 576can be either a real time image of position and orientation detector562, or a representation thereof. It is noted that it is not necessaryfor user interface 544 to display detector image 576 and that detectorimage 576 serves to more clearly describe the disclosed technique.

The clinical staff marks the boundary of tissue image 574 by markings578, on a selected slice of the images produced by imager 546. Imager546, then determines a set of coordinates of a three-dimensional imageof selected tissue 564, according to the coordinates of markings 526 inthe slice. Imager 546 stores this set of coordinates together with thecoordinates of position and orientation detector 562, in storage unit548.

Alternatively, the clinical staff enters a set of coordinates respectiveof a volume of selected tissue 564 relative to the position andorientation of position and orientation detector 562, to storage unit548, via user interface 544. The entered set of coordinates can beeither discrete (i.e., numerical values), or volumetric (e.g., radius ofa sphere from a reference point, height, width and depth of a cube, orradius of the base of a cylinder and the height thereof).

Generally, the planning stage of system 540 as illustrated in FIG. 9B,is performed at a location physically different from the irradiationstage of system 540, as illustrated in FIG. 9C. Hence, wiring 570 isprovided with a connector (not shown), in order to disconnect positionand orientation detector 562 from imager MPS 542 and connect positionand orientation detector 562 to irradiator MPS 550. However, a positionand orientation detector can be provided with wireless connections.

With reference to FIG. 9C, registering module 552 is coupled withstorage unit 548, irradiator MPS 550 and with irradiating unit 554.Position and orientation detector 562 is coupled with irradiator MPS550, via wiring 570.

Irradiator MPS 550 is associated with an X₂, Y₂, Z₂ coordinate system(i.e., coordinate system II). Irradiating unit 554 is calibrated withirradiator MPS 550, such that the position and orientation ofirradiating unit 554 is defined relative to coordinate system II.Position and orientation detector 562 provides a signal respective ofthe position and orientation thereof, to irradiator MPS 550. IrradiatorMPS 550 determines the position and orientation of position andorientation detector 562 in coordinate system II, according to thesignal received from position and orientation detector 562. IrradiatorMPS 550 provides a signal respective of the determined position andorientation to registering module 552.

System 540 can be operated either in a manual mode or an automatic mode.In manual mode, moving mechanism 560 can move irradiating unit 558 toautomatically irradiate a fixed point in space, from differentdirections. However, moving mechanism 560 can not move irradiating unit558 to irradiate points in space, other than the fixed point.

In manual mode, registering module 552 receives data respective of thecoordinate system of irradiating unit 554 (i.e., coordinate system II),from irradiating unit 554. Registering module 552, then registers theposition and orientation of position and orientation detector 562 incoordinate system I, with the position and orientation of position andorientation detector 562 in coordinate system II. The clinical staffpositions the portion of the body of patient 566, such that the positionand orientation of position and orientation detector 562 in coordinatesystem II, is substantially the same as the one determined at theplanning stage (i.e., in coordinate system I). Now, selected tissue 564is located at the fixed point in space, toward which irradiator 558 isset to direct radiations from different directions. At this stage, theclinical staff directs moving mechanism 560 to move irradiator 558, toautomatically irradiate selected tissue 564 from different directions.

In automatic mode of operation of system 540, moving mechanism 560 canadjust the position and orientation of irradiator 558 to irradiatesubstantially any selected point of the body of patient 566. Inaddition, moving mechanism 560 can move irradiating unit 558, toirradiate the selected point of the body of patient 566, from differentdirections.

In automatic mode, registering module 552 retrieves from storage unit548, the data respective of the set of coordinates of the boundary ofselected tissue 564 in coordinate system I, and the coordinates ofposition and orientation detector 562 in coordinate system I.Registering module 552 registers the position and orientation ofposition and orientation detector 562 in coordinate system I, with theposition and orientation of position and orientation detector 562 incoordinate system II.

Registering module 552 provides a signal respective of the set ofcoordinates of the boundary of selected tissue 564 in coordinate systemII and the position and orientation thereof in coordinate system II, tocontroller 556. Controller 556 determines a position and orientation forirradiator 558, to irradiate the boundary of selected tissue 564,according to the data received from registering module 552, respectiveof the set of coordinates of selected tissue 564 in coordinate system IIand provides a respective signal to moving mechanism 560.

Controller 556 also determines a plurality of orientations forirradiator 558, to irradiate selected tissue 564 from differentdirections and controller 556 provides a signal respective of thesedetermined orientations to moving mechanism 560. Moving mechanism 560moves irradiator 558 to the position and orientation determined bycontroller 556, to irradiate selected tissue 564. Moving mechanism 560also moves irradiator 558 automatically, to irradiate selected tissue564 from different directions.

It is noted that in the automatic mode of operation of system 540, thereis no need for the clinical staff to manually position the portion ofthe body of patient 566 relative to irradiator 558. Instead movingmechanism 560 moves irradiator 558 to the appropriate position andorientation.

Controller 556 can be programmed to direct moving mechanism 560 toenable irradiator 558 to irradiate selected tissue 564 from differentdirections, as described herein above in connection with FIG. 7. In casethe scale of coordinate system I and coordinate system II are different,registering module 552 applies the scale factor between these twocoordinate systems, while registering the position and orientation ofposition and orientation detector 562 in coordinate system II, asdescribed herein above in connection with FIG. 1C.

Alternatively, the moving mechanism is coupled with the operating table.In this case, the controller determines a position and orientation ofthe operating table to move the body of patient 566, such thatirradiator 558 can direct radiations toward selected tissue 564. Thecontroller provides a signal respective of the determined orientationsto the moving mechanism and the moving mechanism moves the operatingtable according to the signal received from the controller. In this casetoo, there is no need for the clinical staff to manually move theportion of the body of patient 566 to a position and orientationappropriate for irradiation, instead the moving mechanism performs thismovement.

Alternatively, the moving mechanism is coupled with both the irradiatorand the operating table. In any case, the moving mechanism providesrelative movement between the selected tissue and the irradiator.

Reference is now made to FIG. 10, which is a schematic illustration of amethod for operating the system of FIG. 9A, operative according toanother embodiment of the disclosed technique. In procedure 580, adetector is fixed within the body of a patient, at a selected locationassociated with a selected tissue. With reference to FIG. 9B, positionand orientation detector 562 is implanted within the body of patient522, at the selected location and position and orientation detector 562is coupled with imager MPS 542, via wiring 570.

In procedure 582, a first position and orientation of the detector in afirst coordinate system is detected by a first medical positioningsystem. With reference to FIG. 9B, imager MPS 542 detects the positionand orientation of position and orientation detector 562 in coordinatesystem I and provides a respective signal to imager 546.

In procedure 584, a set of coordinates of the selected tissue in thefirst coordinate system, is associated with the first position andorientation. With reference to FIG. 9B, user interface 544 displays aplanning stage image 572, which includes tissue image 574 and detectorimage 576. The clinical staff marks the boundary of tissue image 574 bymarkings 576, by employing user interface 544. Imager 546 provides theset of coordinates of markings 576 together with the coordinates ofposition and orientation detector 562, for storage in storage unit 548.

Alternatively, the clinical staff enters a set of coordinates ofselected tissue 564 relative to the position and orientation of positionand orientation detector 562, via the user interface and stores this setof coordinates together with the coordinates of position and orientationdetector 562, in storage unit 548.

In procedure 586, a second position and orientation of the detector in asecond coordinate system, is detected by a second medical positioningsystem. With reference to FIG. 9C, patient 522 is located in anirradiation room, which is usually different than the imaging roomillustrated in FIG. 9B and wiring 570 is coupled with irradiator MPS550. Irradiator MPS 550 detects the position and orientation of positionand orientation detector 562 in coordinate system II and provides arespective signal to registering module 552.

In procedure 588, the associated set of coordinates is registered withthe second coordinate system, according to the second position andorientation. With reference to FIG. 9C, registering module 552 retrievesthe set of coordinates from storage unit 548 and registers them withcoordinate system II, according to the position and orientation ofposition and orientation detector 562 in coordinate system II.Registering module 552 further registers the set of coordinates incoordinate system I, with coordinate system II, according to optionaltransformation information for transforming data from coordinate systemI to coordinate system II (e.g., scaling).

Registering module 552 provides a signal respective of the registeredset of coordinates to irradiating unit 554 (procedure 590). In procedure592, the selected tissue is irradiated from different directions,according to the registered set of coordinates. With reference to FIGS.9A and 9C, controller 556 determines a plurality of orientations forirradiator 558 to irradiate the volume of selected tissue 564 indifferent directions and controller 556 provides a respective signal tomoving mechanism 560. Moving mechanism 560 moves irradiator 558according to the signal received from controller 556.

Alternatively, the moving mechanism is coupled with the operating table,to allow movement of a portion of the body of the patient relative tothe irradiator. Further alternatively, the moving mechanism is coupledboth with the operating table and with the irradiator. In all cases, themoving mechanism provides movement of the selected tissue, relative tothe irradiator.

According to a further aspect of the disclosed technique, a medicalpositioning system determines the position and orientation of a detectorcoupled with a medical intervention device which is inserted into thebody of a patient. The medical positioning system directs an imager tomove to an orientation, such that the imager can acquire an image of themaximum possible length of a portion of interest of the medicalintervention device. This portion of interest, is then displayed in adisplay.

Reference is now made to FIG. 11, which is a schematic illustration of asystem for acquiring an image of a medical intervention device,generally referenced 600, constructed and operative according to afurther embodiment of the disclosed technique. System 600 includes animage adjustment system 602, MPS 620, a medical intervention device 604,a device position and orientation detector 606, an imager position andorientation detector 608 and an imager 610. Imager 610 includes asupport structure 612, a moving mechanism 614, a radiation generator 616and a radiation detector 618. Image adjustment system 602 includes anMPS 620 and a processor 622.

Medical intervention device 604 is inserted into the body of a patient624. Patient 624 lies on an operating table 626. Device position andorientation detector 606 is coupled with medical intervention device604, at a region of interest of medical intervention device 604, forexample at a distal end 628 thereof. Imager position and orientationdetector 608 is attached to imager 610. MPS 620 is coupled with deviceposition and orientation detector 606, imager position and orientationdetector 608 and with processor 622. Processor 622 is coupled withmoving mechanism 614. Imager 610 is a device which acquires an image(not shown) of patient 624 (e.g., fluoroscopy, ultrasound, nuclearmagnetic resonance—NMR, optical imaging, nuclear imaging—PET,thermography).

Imager 610 has at least three degrees of freedom. MPS 620 is associatedwith an X, Y, Z coordinate system (i.e., coordinate system I). Imager610 is calibrated with MPS 620, such that the position and orientationof imager 610 is defined relative to coordinate system I.

In the example set forth in FIG. 11, imager 610 is an X-ray type imager(known in the art as C-arm imager). Hence, radiation generator 616 andradiation detector 618 are coupled with support structure 612, such thatradiation generator 616 is located at one side of patient 624 andradiation detector 618 is located at an opposite side of patient 624.Radiation generator 616 and radiation detector 618 are located on aradiation axis (not shown), wherein the radiation axis crosses the bodyof patient 624.

Moving mechanism 614 is coupled with support structure 612, therebyenabling support structure 612 to rotate about the Y axis. Movingmechanism 614 rotates support structure 612, thereby changing theorientation of the radiation axis on the X-Z plane and about the Y axis.Moving mechanism 614 is similar to moving mechanism 560 (FIG. 9A), asdescribed herein above. In the example set forth in FIG. 11, deviceposition and orientation detector 606 is located at distal end 628. Theorientation of distal end 628 is represented by a vector 632 located onthe X-Z plane. In order to obtain an image of the maximum length ofdistal end 628, the radiation axis has to be aligned along, a vector 632located on the X-Z plane, wherein vector 632 is approximately normal tovector 632.

A transmitter (not shown) transmits an electromagnetic signal to deviceposition and orientation detector 606 and to imager position andorientation detector 608. Device position and orientation detector 606provides a signal respective of the position and orientation thereof, toMPS 620, via a wiring 634. Likewise, imager position and orientationdetector 608 provides a signal respective of the position andorientation of imager 610 to MPS 620, via a wiring 636. Alternatively,each of device position and orientation detector 606 and imager positionand orientation detector 608, is coupled with MPS 620 wirelessly.

According to signals received from device position and orientationdetector 606 and from imager position and orientation detector 608, MPS620 detects the position and orientation of device position andorientation detector 606 and of imager position and orientation detector608, respectively. MPS 620 provides a signal respective of the detectedposition and orientation of distal end 628 and of the detected positionand orientation of imager 610 to processor 622.

Processor 622 determines that distal end 628 points along vector 632 andthat the radiation axis has to point along vector 632. Processor 622determines the direction of vector 632, according to signals receivedfrom device position and orientation detector 606 and imager positionand orientation detector 608. Processor 622 provides a signal to movingmechanism 614 to move support structure 612 according to the detectedposition and orientation of imager position and orientation detector608, such that the radiation axis is oriented along vector 632.

Alternatively, system 600 is devoid of imager position and orientationdetector 608. In this case, the coordinates of moving mechanism 614 issynchronized with coordinate system I. Processor 622 determines thedirection of vector 632 according to the signal received from deviceposition and orientation detector 606, alone and directs movingmechanism 614 to move support structure 612, such that the radiationaxis is oriented along vector 632. Processor 622 moves mechanism 614,without receiving any feedback signal respective of the position andorientation of imager 610 at any time.

Further alternatively, system 600 includes a user interface (not shown)coupled with processor 622, wherein the clinical staff enters datarespective of desired orientation ranges of imager 610 to processor 622via the user interface. Processor 622 provides a signal respective ofthe orientation data entered by the clinical staff and moving mechanism614 moves imager 610 according to the signal received from processor622.

Radiation detector 618 detects the radiation which is produced byradiation generator 616 and which passes through a section of the bodyof patient 624, and thus produces an image of this section of the body.Radiation detector 618 provides a signal to a display (not shown) andthe display displays the image of this section of the body. This imageincludes an optimal representation of a portion of interest of medicalintervention device 604 (i.e., an image of the maximum possible lengthof distal end 628).

In the example set forth in FIG. 11, the distal end of the medicalintervention device points along a direction, such that the imager canrotate toward an orientation, at which the radiation axis of the imageris approximately perpendicular to the direction of the distal end of themedical intervention device.

Thus, if the distal end of the medical intervention device points alonga direction, which is not possible to align the radiation axis exactlyperpendicular to this direction, then the imager is moved to anorientation at which an image of the longest projection of the distalend (i.e., maximum possible length of the portion of interest), isobtained.

Alternatively or additionally, a moving mechanism (not shown) similar tomoving mechanism 614 is coupled with operating table and with the MPS.In this case, the MPS directs the moving mechanism to move the operatingtable, such that the imager can acquire an image which includes anoptimal representation of a portion of interest of the medicalintervention device.

Reference is now made to FIG. 12, which is a schematic illustration of amethod for operating the system of FIG. 11, operative according toanother embodiment of the disclosed technique. In procedure 650, amedical intervention device coupled with a position and orientationdetector, is inserted into the body of a patient. With reference to FIG.11, device position and orientation detector 606 is located at a portionof interest (e.g., at distal end 628) of medical intervention device 604and medical intervention device 604 is inserted into the body of patient624. MPS 620, then detects the position and orientation of deviceposition and orientation detector 606 and of imager position andorientation detector 608 (procedure 652). It is noted that the currentposition and orientation of imager 610 can be obtained internally, fromsensors embedded in the imager, or externally, by attaching an MPSsensor to imager 610.

In procedure 654, an imaging orientation of an imager is determinedaccording to the detected positions and orientations, such that theimager can acquire an image of a section of the body, wherein the imageincludes an optimal representation of a portion of interest of themedical intervention device. With reference to FIG. 11, processor 622determines that the portion of interest of medical intervention device604 (i.e., distal end 628), points along vector 622. Processor 622further determines that imager 610 has to be moved to an orientation atwhich the radiation axis thereof points along vector 632.

At this orientation, imager 610 can radiate the body of patient 624along an axis which is approximately perpendicular to the direction ofdistal end 628. Thus, at this orientation, imager 610 can acquire animage of a section of the body of patient 624, wherein the imageincludes an lo optimal representation of a portion of interest ofmedical intervention device 604.

Processor 622 provides a signal to moving mechanism 614 to move imager610 to the orientation determined in procedure 654 (procedure 656).Imager 610 acquires the image (procedure 658) and provides a respectivesignal to a display to display the acquired image (procedure 660).

It will be appreciated by persons skilled in the art that the disclosedtechnique is not limited to what has been particularly shown anddescribed hereinabove. Rather the scope of the disclosed technique isdefined only by the claims, which follow.

1-70. (canceled)
 71. System for adjusting an imager, by means of amoving mechanism, to a desired orientation with respect to a section ofthe body of a patient to acquire a visual representation of saidsection, the visual representation including an optimal representationof a portion of interest of a medical intervention device when insertedinto said section, the system comprising: a medical positioning system;a processor coupled with said medical positioning system and with saidmoving mechanism; and a device position and orientation detector coupledwith said medical intervention device at said portion of interest andwith said medical positioning system, wherein said medical positioningsystem detects a device position and orientation of said device positionand orientation detector, said medical positioning system providing saiddevice position and orientation to said processor, wherein saidprocessor determines said desired orientation according to said deviceposition and orientation, and wherein said processor directs said movingmechanism to move said imager to said desired orientation.
 72. Thesystem according to claim 71 wherein said moving mechanism is configuredfor one of (i) moving said imager; (ii) moving a table, configured forsaid patient, relative to said imager; and (iii) moving both said imagerand said table.
 73. The system according to claim 72, wherein saidmedical positioning system (MPS) is associated with a coordinate system,said imager being calibrated with said MPS.
 74. The system according toclaim 71, further comprising an imager position and orientation detectorcoupled with said imager and with said medical positioning system,wherein said medical positioning system detects an imager position andorientation of said imager position and orientation detector, saidmedical positioning system providing said imager position andorientation to said processor, and wherein said processor determinessaid desired orientation according to said device position andorientation and said imager position and orientation.
 75. The systemaccording to claim 71, wherein said imager comprises: a radiationgenerator located at one side of said body; and a radiation detectorlocated at another side of said body, said radiation detector detectingthe radiation generated by said radiation generator, said portion ofinterest being located between said radiation generator and saidradiation detector, wherein said system further comprises a displaycoupled with said imager, wherein said radiation detector detects saidvisual representation, when said imager is located at said orientation,and wherein said display displays said visual representation.
 76. Thesystem according to claim 71, wherein said moving mechanism has at leastone degree of freedom.
 77. The system according to claim 71, whereinsaid imager operates in a radiation domain selected from the groupconsisting of: nuclear; ultrasonic; and electromagnetic.
 78. The systemaccording to claim 71, wherein said medical intervention device isselected from the group consisting of: catheter; drug deliver unit; andtissue severing unit.
 79. Method for adjusting an imager to a desiredorientation to acquire a visual representation of a section of the bodyof a patient, the visual representation including an optimalrepresentation of a portion of interest of a medical interventiondevice, the method comprising the steps of: detecting a device positionand orientation of a position and orientation detector coupled with saidmedical intervention device, at said portion of interest; determiningsaid desired orientation according to said device position andorientation, such that said imager can acquire said visualrepresentation; and directing a moving mechanism to move said imager tosaid desired orientation.
 80. The method according to claim 79, furthercomprising the step of inserting said medical intervention device intosaid body.
 81. The method according to claim 79, further comprising thesteps of: detecting an imager position and orientation of an imagerposition and orientation detector coupled with said imager; anddetermining the position and orientation of said imager from said imagerposition and orientation.
 82. The method according to claim 79, furthercomprising the step of retrieving an imager position and orientationfrom said imager.
 83. The method according to claim 79, furthercomprising the step of acquiring said visual representation by saidimager.
 84. The method according to claim 83, further comprising thestep of displaying said visual representation.
 85. The method accordingto claim 79, wherein said moving mechanism has at least one degree offreedom.
 86. The method according to claim 79, wherein said imageracquires said visual representation by irradiating said section.
 87. Thesystem according to claim 71, further comprising: a user interfaceconfigured to receive an input from a user respective of said desiredorientation of said imager.
 88. The system of claim 87 wherein saidmedical positioning system (MPS) is associated with a coordinate system,said moving mechanism being synchronized with said coordinate system,said processor being configured to determine a vector indicative of adirection of said medical intervention device according to said deviceposition and orientation, said processor being configured to directmoving mechanism so as to move said imager such that an axis associatedwith said imager is in a desired relationship with said determinedvector.
 89. The system of claim 88 wherein in said desired relationship,said axis is normal to said vector.
 90. The system of claim 87 whereinsaid user interface is configured to receive said input as a userdesignation of said desired orientation for said imager on athree-dimensional visual representation of said section of said body ofsaid patient.